cfra

#!/usr/bin/env python3
import json
import sys

try:
    file_path = sys.argv[1]
except IndexError:
    sys.stderr.write(f"Usage: {sys.argv[0]} <file_path>\n")
    sys.exit(1)

cfra

---

- name: Reload networking (in-band)
  service:
    name: networking
    state: reloaded

- name: Reload networking (out-of-band)
  shell: ifreload --allow=mgmt
  async: 45

cfra

Deploy workadventure with Kubernetes

Some slight adaptation of deeployer.libsonnet is necessary. My diff looks like this:

diff --git a/deeployer.libsonnet b/deeployer.libsonnet
index 8957194..357422d 100644
--- a/deeployer.libsonnet
+++ b/deeployer.libsonnet
@@ -1,9 +1,9 @@

cfra

Using "obscure" libraries with the Heroku Python buildpack

For a project I required dm.xmlsec.binding on Heroku.

To build this package on Ubuntu, libxmlsec1-dev needs to be installed.

Okay, let's add heroku-buildpack-apt and the following Aptfile:

libxmlsec1-dev

cfra

Colors in Video

Disclaimer: I don't have a deep understanding of this topic, so take everything I have written up here with a grain of salt. This also is all from the perspective of 8 bit SDR video. HDR video is probably a whole other can of worms.

YCbCr and Chroma Subsampling

This describes my observations about Converting from RGB to video, attempting to match colors when encoding using libx264.

cfra

Zoom U-44 PulseAudio Setup

Problem Statement

The Zoom U-44 works out of the box with recent Linux versions.

By default, PulseAudio will register it as a single sink with 4 output channels. As the U-44 is organized to have two stereo pairs for outputs, there are situations where it is more useful to have 2 separate sinks available, each playing back to one of the two stereo pairs.

cfra

Tunneling Ethernet Over SSH With Socat and Tap Devices

There are circumstances where one wants to attach the local machine to the same layer 2 ethernet segment, which a remote machine is connected to, with the only available transport being SSH.

While this solution has quite some shortcomings and should not be used to replace a real VPN, it can be beneficial e.g. for debugging network issues remotely.

cfra

Adding a new TLV and SubTLVs to FRR's isisd

Protocol description

For this first example, we are going to add a TLV called hundred with the currently unassigned codepoint 100.

That TLV has the following assumed format:

• one octet: type this is 100

cfra

Some programs might create network namespaces without registering them in /run/netns as iproute2 does. This makes it hard to access them with readily available tools like ip netns exec. However, there is a way to register those network namespace, after they have been created.

The following session creates and enters an unnamed namespace:

# unshare -n bash
# ip a l
1: lo:  mtu 65536 qdisc noop state DOWN group default qlen 1000

cfra

Installing eve-ng on digitalocean

1. Create an Ubuntu 16.04 Droplet
2. Set a root passwd

passwd root